Skimmer-type oil booms are well known in the prior art, wherein a floating boom assembly is towed across the surface of a body of water having a floating oil slick thereon, and some means are provided to gather the oil in a central area for removal by suction or mechanical devices. Various floating boom structures of this type can be seen in such recent prior art patents as U.S. Pat. Nos. 3,688,506; 3,686,870 and 3,771,662, to name just a few examples.
The present invention, however, has particular application in connection with an oil boom as described in applicant's copending application Ser. No. 582,271, filed March, 1975, now U.S. Pat. No. 3,979,291, entitled "Oil Boom," that application being a continuation of Ser. No. 422,603, filed Dec. 6, 1973, now abandoned. (The latter application was co-pending with the parent case of the present application).
In applicant's co-pending oil boom application, a pair of boom segments are in the form of parallel, flexible barrier walls that float on the surface of the water, the barriers being supported upright by a rigid framework to which the walls are further connected by means of resilient connecting elements.
The oil boom is towed in a direction transverse to the lengths of the barrier walls, and surface oil and other floating contamination is deflected by the barriers towards surface skimmers located at one end of the oil boom assembly. The skimmers are floating weir units and also are subjected to oncoming surface current flow as the boom is towed across the water surface.
It has been discovered that under certain conditions of operation, the flow of water approaching a surface skimmer of the floating weir type will stand up in front of the skimmer unit somewhat in the manner of a bow wave on a vessel, and may prevent efficient removal of floating oil from the water's surface unless a deeper skimming action is taken to eliminate the effect of the standing wave in front of the skimmer. This may occur when the boom is towed or in a stationary installation where a river current is used to carry the oil to the skimmer and where the current of the river is relatively rapid.
It has therefore become apparent to the inventor that a means for controlling the level of surface water directly in front of the skimmer unit would alleviate the difficulty observed and would enhance the operation of the floating surface skimmer unit. It has also been observed that it is desirable to stabilize the area of water immediately in front of the skimmer by a suitable means.